1. Field of the Invention
The present invention relates to a first stage amplifier circuit configured to receive a signal from an external circuit of the semiconductor integrated circuit.
2. Description of the Related Art
Semiconductor integrated circuits include pads (which will be collectively referred to as “I/O pads” hereafter) which allow external signals to be received from, or signals to be output to, an external circuit. Furthermore, in many cases, semiconductor integrated circuits include a first stage amplifier circuit having a high input impedance as a first stage component connected to the I/O pads. As such a first stage amplifier circuit, a non-inverting amplifier circuit or an inverting amplifier circuit using operational amplifiers and resistors is employed.